
package com.android.fitnesscenter.download;

import java.io.File;
import java.io.RandomAccessFile;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.LinkedHashMap;
import java.util.Locale;
import java.util.Map;
import java.util.UUID;
import java.util.concurrent.ConcurrentHashMap;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import android.content.Context;

import com.android.fitnesscenter.utils.Loger;

public class FileDownloader {
    // private Context context;
    // private FileService fileService;
    // 已下载文件长度
    private int downloadSize = 0;
    // 原始文件长度
    private int fileSize = 0;
    // /线程数
    private DownloadThread[] threads;
    // 本地保存文件
    private File saveFile;
    // 缓存各线程下载的长度
    private Map<Integer, Integer> data = new ConcurrentHashMap<Integer, Integer>();
    // 每条线程下载的长度
    private int block;
    // 下载路径
    private String downloadUrl;

    // 获取线程数
    public int getThreadSize() {
        return threads.length;
    }

    /**
     * 获取文件大小
     * 
     * @return
     */
    public int getFileSize() {
        return fileSize;
    }

    /**
     * 累计已下载大小
     * 
     * @param size
     */
    protected synchronized void append(int size) {
        downloadSize += size;
    }

    // /**
    // * 更新指定线程最后下载的位置
    // *
    // * @param threadId 线程id
    // * @param pos 最后下载的位置
    // */
    // protected synchronized void update(int threadId, int pos) {
    // this.data.put(threadId, pos);
    // this.fileService.update(this.downloadUrl, this.data);
    // }

    /**
     * 文件下载构造器
     * 
     * @param downloadUrl 下载路径
     * @param fileSaveDir 文件保存目录
     * @param threadNum 下载线程数
     */
    public FileDownloader(Context context, String downloadUrl, File fileSaveDir, int threadNum) {
        try {
            // this.context = context;
            this.downloadUrl = downloadUrl;
            // fileService = new FileService(this.context);
            URL url = new URL(this.downloadUrl);
            if (!fileSaveDir.exists()) fileSaveDir.mkdirs();
            this.threads = new DownloadThread[threadNum];
            Loger.e("FileDownloader ---url----" + url);
            HttpURLConnection conn = (HttpURLConnection) url.openConnection();
            conn.setConnectTimeout(5 * 1000);
            conn.setRequestMethod("GET");
            conn.setRequestProperty(
                    "Accept",
                    "image/gif, image/jpeg, image/pjpeg, image/pjpeg, application/x-shockwave-flash, application/xaml+xml, application/vnd.ms-xpsdocument, application/x-ms-xbap, application/x-ms-application, application/vnd.ms-excel, application/vnd.ms-powerpoint, application/msword, */*");
            conn.setRequestProperty("Accept-Language", "zh-CN");
            conn.setRequestProperty("Referer", downloadUrl);
            conn.setRequestProperty("Charset", "UTF-8");
            conn.setRequestProperty(
                    "User-Agent",
                    "Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 5.2; Trident/4.0; .NET CLR 1.1.4322; .NET CLR 2.0.50727; .NET CLR 3.0.04506.30; .NET CLR 3.0.4506.2152; .NET CLR 3.5.30729)");
            conn.setRequestProperty("Connection", "Keep-Alive");
            conn.connect();
            Loger.e("FileDownloader -------------------" + conn.getResponseCode());
            if (conn.getResponseCode() == 200) {
                // 根据响应获取文件大小
                this.fileSize = conn.getContentLength();
                if (this.fileSize <= 0) throw new RuntimeException("Unkown file size ");
                // 获取文件名称
                String filename = getFileName(conn);
                // 构建保存文件
                this.saveFile = new File(fileSaveDir, filename);
                // 获取下载记录
                // Map<Integer, Integer> logdata =
                // fileService.getData(downloadUrl);
                Loger.e("FileDownloader logdata getData fileSize is " + fileSize);
                // 如果存在下载记录
                // if (logdata.size() > 0) {
                // // 把各条线程已经下载的数据长度放入data中
                // for (Map.Entry<Integer, Integer> entry : logdata.entrySet())
                // {
                // data.put(entry.getKey(), entry.getValue());
                // }
                // }
                // 下面计算所有线程已经下载的数据长度
                if (this.data.size() == this.threads.length) {
                    for (int i = 0; i < this.threads.length; i++) {
                        this.downloadSize += this.data.get(i + 1);
                    }
                    Loger.e("FileDownloader 已经下载的长度" + this.downloadSize);
                }
                // 计算每条线程下载的数据长度
                this.block = (this.fileSize % this.threads.length) == 0 ? this.fileSize / this.threads.length
                        : this.fileSize / this.threads.length + 1;
            } else {
                Loger.e("FileDownloader server no response ");
                throw new RuntimeException("server no response ");
            }
        } catch (Exception e) {
            Loger.e("FileDownloader exception is " + e.toString());
            throw new RuntimeException("don't connection this url");
        }
    }

    /**
     * 获取文件名
     */
    private String getFileName(HttpURLConnection conn) {
        String filename = this.downloadUrl.substring(this.downloadUrl.lastIndexOf('/') + 1);
        if (filename == null || "".equals(filename.trim())) {// 如果获取不到文件名称
            for (int i = 0;; i++) {
                String mine = conn.getHeaderField(i);
                if (mine == null) break;
                if ("content-disposition".equals(conn.getHeaderFieldKey(i).toLowerCase(Locale.getDefault()))) {
                    Matcher m = Pattern.compile(".*filename=(.*)").matcher(mine.toLowerCase(Locale.getDefault()));
                    if (m.find()) return m.group(1);
                }
            }
            filename = UUID.randomUUID() + ".tmp";// 默认取一个文件名
        }
        return filename;
    }

    /**
     * 开始下载文件
     * 
     * @param listener 监听下载数量的变化,如果不需要了解实时下载的数量,可以设置为null
     * @return 已下载文件大小
     * @throws Exception
     */
    public int download(DownloadProgressListener listener) throws Exception {
        try {
            // 创建本地文件
            RandomAccessFile randOut = new RandomAccessFile(this.saveFile, "rw");
            try {
                if (this.fileSize > 0) {
                    randOut.setLength(this.fileSize);
                }
            } finally {
                if (randOut != null) {
                    randOut.close();
                }
            }
            URL url = new URL(this.downloadUrl);
            if (this.data.size() != this.threads.length) {
                this.data.clear();
                for (int i = 0; i < this.threads.length; i++) {
                    // 初始化每条线程已经下载的数据长度为0
                    this.data.put(i + 1, 0);
                }
            }
            // 开启线程进行下载
            for (int i = 0; i < this.threads.length; i++) {
                int downLength = this.data.get(i + 1);
                // 判断线程是否已经完成下载,否则继续下载
                if (downLength < this.block && this.downloadSize < this.fileSize) {
                    this.threads[i] = new DownloadThread(this, url, this.saveFile, this.block, this.data.get(i + 1),
                            i + 1);
                    this.threads[i].setPriority(7);// 可删除这条
                    this.threads[i].start();
                } else {
                    this.threads[i] = null;
                }
            }
            Loger.e("FileDownloader save this.block is " + this.block);
            // this.fileService.save(this.downloadUrl, this.data);
            // 下载未完成
            boolean notFinish = true;
            // 循环判断所有线程是否完成下载
            while (notFinish) {
                Thread.sleep(10);
                // 假定全部线程下载完成
                notFinish = false;
                for (int i = 0; i < this.threads.length; i++) {
                    // 如果发现线程未完成下载
                    if (this.threads[i] != null && !this.threads[i].isFinish()) {
                        // 设置标志为下载没有完成
                        notFinish = true;
                        // 如果下载失败,再重新下载
                        if (this.threads[i].getDownLength() == -1) {
                            this.threads[i] = new DownloadThread(this, url, this.saveFile, this.block,
                                    this.data.get(i + 1), i + 1);
                            this.threads[i].setPriority(7);
                            this.threads[i].start();
                        }
                    }
                }
                // 通知目前已经下载完成的数据长度
                if (listener != null) {
                    listener.onDownloadSize(this.downloadSize, this.saveFile);
                }
            }
            // 删除数据库中下载信息
            // fileService.delete(this.downloadUrl);
        } catch (Exception e) {
            Loger.e("FileDownloader exception is " + e.toString());
            throw new Exception("file download fail");
        }
        return this.downloadSize;
    }

    /**
     * 获取Http响应头字段
     * 
     * @param http
     * @return
     */
    public static Map<String, String> getHttpResponseHeader(HttpURLConnection http) {
        Map<String, String> header = new LinkedHashMap<String, String>();
        for (int i = 0;; i++) {
            String mine = http.getHeaderField(i);
            if (mine == null) break;
            header.put(http.getHeaderFieldKey(i), mine);
        }
        return header;
    }

    /**
     * 打印Http头字段
     * 
     * @param http
     */
    public static void printResponseHeader(HttpURLConnection http) {
        Map<String, String> header = getHttpResponseHeader(http);
        for (Map.Entry<String, String> entry : header.entrySet()) {
            String key = entry.getKey() != null ? entry.getKey() + ":" : "";
            Loger.e("FileDownloader key is " + key + entry.getValue());
        }
    }

}
